From 4a6fe77b38d781936d7e7d2543f041c8babcb089 Mon Sep 17 00:00:00 2001
From: Alaux <73968015+MrAlaux@users.noreply.github.com>
Date: Sat, 14 Dec 2024 00:31:46 -0300
Subject: [PATCH] Hitscan-trail interval setting, and more

Also tweaked description of the `bobbing_style` CVAR.
---
 src/g_game.c |  7 ++++++-
 src/p_map.c  | 21 +++++++++++++--------
 src/p_map.h  |  1 +
 3 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/src/g_game.c b/src/g_game.c
index 9972a6d6f..360c36b72 100644
--- a/src/g_game.c
+++ b/src/g_game.c
@@ -6231,7 +6231,7 @@ void G_BindWeapVariables(void)
 
   M_BindNum("bobbing_style", &bobbing_style, NULL,
             0, 0, 6, ss_weap, wad_yes,
-            "Weapon Bobbing Style");
+            "Weapon bobbing style");
 
   M_BindBool("weapon_inertia", &weapon_inertia, NULL,
              false, ss_weap, wad_yes, "Weapon inertia");
@@ -6251,6 +6251,11 @@ void G_BindWeapVariables(void)
   M_BindBool("sx_fix", &sx_fix, NULL,
              false, ss_none, wad_yes, "Correct centering of first-person sprites");
 
+  // (CFG-only)
+  M_BindNum("hitscan_trail_interval", &hitscan_trail_interval, NULL,
+            8, 1, 16, ss_none, wad_yes,
+            "Distance between particles of hitscan trails, in units");
+
   // [Nugget] ---------------------------------------------------------------/
 
 #define BIND_WEAP(num, v, help) \
diff --git a/src/p_map.c b/src/p_map.c
index 38a72eba3..8f447994d 100644
--- a/src/p_map.c
+++ b/src/p_map.c
@@ -48,6 +48,7 @@
 #include "z_zone.h"
 
 // [Nugget]
+#include <math.h>
 #include "g_game.h"
 #include "p_tick.h"
 
@@ -98,6 +99,8 @@ msecnode_t *sector_list = NULL;                             // phares 3/16/98
 
 // [Nugget] Hitscan trails /--------------------------------------------------
 
+int hitscan_trail_interval;
+
 static int show_hitscan_trails = 0;
 
 static fixed_t distance_travelled = 0;
@@ -123,7 +126,7 @@ void P_SpawnHitscanTrail(fixed_t x, fixed_t y, fixed_t z,
                          angle_t angle, fixed_t slope,
                          fixed_t range, fixed_t distance)
 {
-  const int scaled_range = (range >> FRACBITS) / 8;
+  const int scaled_range = (range >> FRACBITS) / hitscan_trail_interval;
 
   if (!scaled_range) { return; }
 
@@ -136,16 +139,18 @@ void P_SpawnHitscanTrail(fixed_t x, fixed_t y, fixed_t z,
                 ystep = (y2 - y) / scaled_range,
                 zstep = (slope * (range >> FRACBITS)) / scaled_range;
 
-  const int scaled_distance = (distance >> FRACBITS) / 8;
+  const int num_particles = (distance >> FRACBITS) / hitscan_trail_interval;
 
-  for (int i = 5;  i < scaled_distance;  i++)
+  // Don't spawn particles less than 40 units away
+  for (int i = ceil((float) 40 / hitscan_trail_interval);  i < num_particles;  i++)
   {
-    mobj_t *const puff = P_SpawnVisualMobj(x + xstep * i,
-                                           y + ystep * i,
-                                           z + zstep * i,
-                                           AS_TRAIL1);
+    const fixed_t xdist = xstep * i,  ydist = ystep * i,  zdist = zstep * i;
+
+    mobj_t *const puff = P_SpawnVisualMobj(x + xdist, y + ydist, z + zdist, AS_TRAIL1);
+
+    // One more tic every 128 units
+    puff->alttics += (P_AproxDistance(xdist, ydist) >> FRACBITS) / 128;
 
-    puff->alttics += i / 16;
     puff->flags |= MF_NOGRAVITY;
     puff->tranmap = trail_tranmap;
   }
diff --git a/src/p_map.h b/src/p_map.h
index d80459049..f457c93aa 100644
--- a/src/p_map.h
+++ b/src/p_map.h
@@ -30,6 +30,7 @@ struct player_s;
 struct sector_s;
 
 // [Nugget] CVARs
+extern int hitscan_trail_interval;
 extern boolean comp_lscollision;
 extern boolean comp_lsamnesia;